In oilfield operations, an annulus, such as an annulus between a tubular and another tubular (e.g., a casing string) or an annulus between a tubular and a wellbore (e.g., a bare wellbore), can be sealed. Sealing an annulus can include fluidly sealing the annulus with or without a pressure differential on opposite sides of the seal. Substantial pressure differentials across a seal can induce failure of the seal and can result in substantial loss of time, money, and equipment, and can even result in harm to individuals. Additionally, expanding a wellbore seal can induce substantial deformation and internal stress on a sealing element, which can increase the chance of failure (e.g., due to breaking or tearing). The design of wellbore seals is thus limited in structure and material choice in order to minimize the chance of failure.